Cardiovascular disease (CVD) morbidity and mortality risk can be reduced through early detection and evidence-based disease management, yet many people receive CVD preventive services late or never, and significant disparities persist. Oregon6s recent Medicaid 3lottery4 provides a unique natural experiment to evaluate how insurance policy changes impact utilization of CVD preventive services among persons receiving care in the safety net. In 2008, the Oregon Medicaid program used a 3lottery4 to allocate limited insurance resources to low-income adults who did not categorically qualify for traditional Medicaid coverage. Thousands of low-income adults were randomly selected to apply for Medicaid coverage; many others were not selected. This natural experiment is the first population-level randomization of insurance coverage since Rand6s 1971- 1982 experiment. The proposed study will use electronic health record (EHR) data from a network of >100 community health centers to assess how receipt of CVD preventive care was impacted by Oregon's Medicaid lottery, among established patients in safety net clinics. Building on our prior experience, we will link EHR data from this network of community health centers to Oregon Medicaid enrollment and billing records. We will partner with OCHIN, the non-profit organization that provides and maintains this networked safety net EHR, serving >100 clinic sites with >500,000 adult patients in Oregon. OCHIN has an enterprise-wide master patient index, with the unprecedented asset of one unique patient identifier across all sites. Our goal is to test the hypothesis that gaining public insurance coverage is associated with higher rates of receipt of CVD primary and secondary preventive care among individuals with a usual and continuous source of primary care. The proposed work will also demonstrate the value of using a unique safety net clinic EHR database in research to evaluate the impact of practice and policy interventions on vulnerable populations, with potential for widespread replication. We propose three Specific Aims: Aim 1: To compare pre-post rates of primary and secondary CVD preventive services utilization among OCHIN patients randomized to the Medicaid coverage group in Oregon6s Medicaid insurance lottery (intervention group). Aim 2: To compare post-intervention rates of primary and secondary CVD preventive services utilization among OCHIN patients randomized to the Medicaid coverage group (intervention group), compared to those not in the coverage group (comparison group). Aim 3: To examine longitudinal associations between health insurance continuity and rates of receipt of primary and secondary CVD preventive services among all OCHIN patients. Through our partnership of community organizations, state policy makers, and academic researchers, the data tools and methods developed and tested here will provide an unprecedented resource for future practice, policy, and community interventions and evaluations.